Precision will be reduced, but yield will be increased

Optimisation of a PCR reaction is often a compromise between the competing demands for precision, efficiency and yield. Although the specific effects may vary, generally, increasing the annealing temperature will increase non-specific primer binding and reduce precision. Increasing the length of the elongation phase will reduce the proportion of incomplete newly-synthesised strands and therefore increase yield. In this case, the potential effect on efficiency is unclear. Increasing the elongation phase would increase the reaction time, but the time taken to ramp down to a lower annealing temperature would be reduced.

What would the expected effect be on a PCR reaction if the primers used were slightly shorter and more variable than the intended oligonucleotide sequences?

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#Question id: 14857

#SCPH06 I Botany

A man has 9 friends (4 men and 5 women). In how many ways can he invite them, if there have to be exactly 3 women in the invitees ?

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#Question id: 14858

#SCPH06 I Botany

Given two events A and B and P(A) = 1/4, P(B/A) = 1/2, P(A/B) = 1/4. Which of the following is true?

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#Question id: 14859

#SCPH05 I Biotechnology

Liquid from a brewery fermenter can be considered to contain 10% ethanol and 90% water. 50000 kg h-1 of this fermentation product are pumped to a distillation column on the factory site. Under current operating conditions a distillate of 45% ethanol and 55% water is produced from the top of the column at a rate one-tenth that of the feed.

 What is the composition of the waste 'bottoms' from the still?

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#Question id: 14860

#SCPH05 I Biotechnology

A fermentation slurry containing Streptomyces kanamyceticus cells is filtered using a continuous rotary vacuum filter. 120 kg h^{- 1} slurry is fed to the filter; 1 kg slurry contains 60 g cell solids. To improve filtration rates, particles of diatomaceous-earth filter aid are added at a rate of 10 kg h^{- 1}. The concentration of kanamycin in the slurry is 0.05% by weight. Liquid filtrate is collected at a rate of 112 kg h^-1; the concentration of kanamycin in the filtrate is 0.045% (w/w). Filter cake containing cells and filter aid is continuously removed from the filter cloth.

 What percentage liquid is the filter cake?

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#Question id: 14861

#SCPH05 I Biotechnology

A fermentation slurry containing Streptomyces kanamyceticus cells is filtered using a continuous rotary vacuum filter. 120 kg h^{- 1} slurry is fed to the filter; 1 kg slurry contains 60 g cell solids. To improve filtration rates, particles of diatomaceous-earth filter aid are added at a rate of 10 kg h^{- 1}. The concentration of kanamycin in the slurry is 0.05% by weight. Liquid filtrate is collected at a rate of 112 kg h^-1; the concentration of kanamycin in the filtrate is 0.045% (w/w). Filter cake containing cells and filter aid is continuously removed from the filter cloth.

If the concentration of kanamycin in the filter-cake liquid is the same as in the filtrate, how much kanamycin is absorbed per kg filter aid?.,..... 10^-4

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#Question id: 14891

#SCPH05 I Biotechnology

What do you mean by idiophone?